/*
 * Copyright (c) 2015 The Jupiter Project
 *
 * Licensed under the Apache License, version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.inyourcode.core.transport.netty.handler;

import com.inyourcode.core.transport.api.Acknowledge;
import com.inyourcode.core.transport.api.JProtocolHeader;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;

/**
 * ACK encoder.
 *
 * jupiter
 * org.jupiter.transport.netty.handler
 *
 * @author jiachun.fjc
 */
@ChannelHandler.Sharable
public class AcknowledgeEncoder extends MessageToByteEncoder<Acknowledge> {

    @Override
    protected void encode(ChannelHandlerContext ctx, Acknowledge ack, ByteBuf out) throws Exception {
        out.writeShort(JProtocolHeader.MAGIC)
                .writeByte(JProtocolHeader.ACK)
                .writeByte(0)
                .writeLong(ack.sequence())
                .writeInt(0);
    }
}
